Methods and apparatus for traffic management in multi-mode switching DWDM networks

ABSTRACT

A Wavelength Division Multiplexing (WDM) multi-mode switching system and method and method provides concurrent switching in various switching modes including, but not limited to, an electronic packet switching (EPS) mode, optical circuit switching (OCS) mode, and optical burst switching (OBS) mode. Edge routers in the WDM multi-mode switching systems may provide a traffic management module that processes incoming data and routes the data for transmission in an electronic packet switching (EPS), optical burst switching (OBS), or optical circuit switching (OCS) modes via a WDM link.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

This invention was made with government support under Grant Nos.CNS-0708613, CNS-0923481 and ECCS-0926006 awarded by the NationalScience Foundation. The government has certain rights in the invention.

RELATED APPLICATIONS

This application is a divisional of U.S. Nonprovisional application Ser.No. 13/434,597, filed Mar. 29, 2012, which claims the benefit of U.S.Provisional Patent Application No. 61/469,337, filed on Mar. 30, 2011,which are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to a method for enhancing trafficmanagement in optical networks. More specifically, the present inventionenables efficient dynamic packet traffic management in Dense WavelengthDivision Multiplexing (DWDM) networks.

BACKGROUND OF INVENTION

With the advent of 10 Gigabit Ethernet and Fiber-to-the-Home (FTTH) withthe Passive Optical Network (PON), residential user data rate isexpected to exceed 100 Mb/s in the near future, and over 1 Gb/s in thelong term, while enterprise users will enjoy 10 Gb/s connectivity. Inaddition, data-intensive users are expected to have 10 to 100 TB datasets to be delivered within 24 hours. To scale the Internet overexisting network infrastructure, Dense Wavelength Division Multiplexing(DWDM) technology has made it possible to carry hundreds of wavelengthchannels over a single optical fiber at rates of 10 Gb/s and beyond.DWDM transmission has been widely deployed in long haul service providernetworks, and is increasingly being deployed in metro service providernetworks and for enterprise data center connectivity applications. Inaddition, WDM PON can deliver dedicated (unshared) bandwidth of over 1Gb/s to residential users. DWDM has become the technology of choice forcommunication networks. While DWDM is universally used in transmission,different switching technologies can be used to direct input data to theoutput at router nodes. Current switching technologies can becharacterized into electronic switching and optical switchingtechnologies based on how data is processed in the router.

Electronic switching technology, also known as electronic packetswitching (EPS), converts DWDM optical signals to electronic signals,and processes data (usually in the form of packets) electronically.After packets are routed to the destined output, they are converted backto an optical signal, and sent on DWDM links toward the downstreamrouter. However, as the number of DWDM channels increases, theoptical/electrical/optical (O/E/O) conversion required by electronicswitching adds significantly to the overall system cost. For example,while it is technologically feasible to carry 512 wavelengths in asingle optical fiber, it requires 512 O/E/O pairs in EPS routers, justto terminate a single DWDM link.

Optical switching technologies, on the other hand, allow DWDM channelsto pass the router node optically, greatly reducing the cost to deployDWDM channels over existing network infrastructure. Optical switchingcan be further divided into 3 technologies: a) Optical circuit switching(OCS), b) Optical packet switching (OPS), and c) Optical burst switching(OBS). In OCS, switching decisions are made at the wavelength level, anddata passes through routers along pre-established lightpaths. Althoughthe technology has been available for the past several years, itsdeployment has been slow due to its coarse granularity which limits itsapplication in supporting dynamic traffic. OPS overcomes this limitationin that it is to switch packet level data optically. It is unlikely thatOPS will be available in the foreseeable future, largely due to the lackof random access optical buffers, and the synchronization issuesassociated with the packet header and payload. OBS provides agranularity between optical circuit switching and optical packetswitching. It allows the control header to establish an optical datapath before data arrives at the optical switching fabric so that nooptical buffer is needed. In addition, the decoupling of the controlheader and the data (burst) also bypasses the synchronization problemthat OPS experiences. Currently, OBS is considered the most promisingoptical switching technology.

Unfortunately, there is no single switching technology that can scalecost-effectively with the number of DWDM channels while meeting thediverse needs of heterogeneous applications. Internet traffic may beheterogeneous, embracing all the data generated by applications thatdiffer greatly in nature (e.g., VoIP, Video-on-Demand (VoD)), IPTV,3G/WiMax, Virtual-Private-Network (VPN), and 10 Gigabit Ethernet). Itseems that no single switching technology (EPS, OCS or OBS) can claimvictory over all applications. Although optical switching technologieshave advantages for scaling up DWDM systems, neither OCS nor OBS canswitch at the packet level. However, fine packet level granularity isdesirable when transporting short, latency sensitive messages, such asTCP (Transmission Control Protocol) acknowledgements. Even between thetwo optical switching technologies, OCS and OBS, it is hard to declare awinner for all types of applications. While it is clear that OBSperforms well for most of bursty Internet traffic, OCS is more suitablefor applications such as high energy physics that require sustained,long-term full channel bandwidth (i.e. 10 Gb/s and above). OCS is also abetter fit for mission critical applications which cannot tolerate anydata loss or delay. One can always build separate networks usingdifferent switching technologies to meet the respective needs ofapplications. However, for some applications, this implies a highercapital investment, separate management issues for each type ofnetworks, and less flexibility; for others, unfortunately, there is nosingle type of network that can best fit the need for the applicationbecause of the characteristics of different types of messages within theapplication. Although attempts have been made to support specificapplications in the network, none of them address the DWDM channelscaling issue.

In order to solve the dilemma, with both the applications and cost ofsystem scaling in mind, an approach for traffic management in DWDM-basedcommunication networks is discussed herein. The approach enables dynamicpacket traffic management in DWDM networks.

SUMMARY OF THE INVENTION

Methods and apparatuses for traffic management discuss herein providetraffic management in multi-mode switching DWDM networks with finegranularity. These methods and apparatuses provide dynamic packetservices in DWDM networks. These methods and apparatuses provide anoptical router that supports dynamic traffic management at packetgranularity. Edge routers in the DWDM multi-mode switching systems mayprovide a traffic management module that processes incoming data androutes the data for transmission in an electronic packet switching(EPS), optical burst switching (OBS), or optical circuit switching (OCS)modes via a DWDM link.

In one illustrative implementation, an edge router system for multi-modeswitching comprises a traffic management module receiving data from oneor more sources. The traffic management module comprises a multi-modepacket processor receiving said data that processes it for transmissionin EPS, OBS, and/or OCS modes. An EPS mode processor may receive a firstportion of the data from the packet processor, wherein the EPS modeprocessor assembles the first portion of data for transmission in an EPSmode on a first wavelength. An OBS mode processor may receive a secondportion of the data from the packet processor, wherein the OBS modeprocessor assembles the second portion of data into burst fortransmission in an OBS mode on a second wavelength. An OCS modeprocessor may receive a third portion of the data from the packetprocessor, wherein the OCS mode processor transmits the third portion ofdata in an OCS mode on a third wavelength. A switching control coupledto the multi-mode packet processor generates control packets for EPS,OCS, and OBS data. A multiplexer combines the control packets and theEPS, OCS, and OBS data for output to a WDM link.

In another illustrative implementation, a method for multi-mode edgerouting comprising receiving data from one or more sources at an edgerouter for transmission via a WDM link. A first portion of the data maybe routed to an electronic packet switching (EPS) mode processor thatassembles the first portion of data in an EPS mode on a firstwavelength. A second portion of the data may be routed to an opticalburst switching (OBS) mode processor that assembles the second portionof data into burst for transmission in an OBS mode on a secondwavelength. A third portion of the data may be routed to an opticalcircuit switching (OCS) mode processor that transmits the third portionof data in an OCS mode on a third wavelength. The EPS, OBS, and OCS dataare combined for output to a WDM link.

The foregoing has outlined rather broadly various features of thepresent disclosure in order that the detailed description that followsmay be better understood. Additional features and advantages of thedisclosure will be described hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure, and theadvantages thereof, reference is now made to the following descriptionsto be taken in conjunction with the accompanying drawings describingspecific embodiments of the disclosure, wherein:

FIG. 1 is an illustrative implementation of Reconfigurable AsymmetricOptical Burst Switching (RA-OBS) network architecture;

FIG. 2 is an illustrative implementation of a RA-OBS edge routerarchitecture;

FIG. 3(a) is an illustrative implementation of an integrated multi-modetraffic management module that handles EPS, OBS and EPS connections;

FIG. 3(b) is an illustrative implementation of an integrated multi-modetraffic management module that provides packet level services in EPSconnections;

FIG. 3(c) is an illustrative implementation of an integrated multi-modetraffic management module that provides packet level services in OBSconnections;

FIG. 3(d) is an illustrative implementation of an integrated multi-modetraffic management module that provides packet level services in OCSconnections;

FIG. 3(e) is an illustrative implementation of an integrated multi-modetraffic management module that provides packet level services in EPS,OBS, OCS connections at the same time;

FIG. 4 is an illustrative implementation of an integrated multi-modetraffic management module;

FIG. 5 is an illustrative implementation of an EPS mode processor;

FIG. 6 is an illustrative implementation of an OBS mode processor;

FIG. 7 is an illustrative implementation of supporting real-time andnon-real-time traffic in a dynamic multi-mode packet scheduler;

FIG. 8(a) is an illustrative implementation of supporting real-time andnon-real-time traffic in a OBS mode processor;

FIG. 8(b) is an illustrative implementation of supporting real-time andnon-real-time traffic in the OCS mode processor;

FIG. 9 is an illustrative implementation of supporting per flow/classtraffic in a dynamic multi-mode packet scheduler;

FIG. 10(a) is an illustrative implementation of supporting perflow/class traffic in an OBS mode processor;

FIG. 10(b) is an illustrative implementation of supporting perflow/class traffic in an OCS mode processor;

FIG. 11 is an illustrative implementation of sequence control in adynamic multi-mode packet scheduler;

FIG. 12 is an illustrative implementation of sequence control in an OBSmode processor;

FIG. 13 is an illustrative implementation of energy efficiency controlin a dynamic multi-mode packet scheduler;

FIG. 14 is an illustrative implementation of energy efficiency controlin an OBS mode processor;

FIG. 15(a) is an illustrative implementation of energy efficiencycontrol in a multi-mode burst assembler;

FIG. 15(b) is an illustrative implementation of energy efficiencycontrol in a multi-mode burst transmission control;

FIG. 16 is an illustrative implementation of energy efficiency controlin a dynamic multi-mode packet scheduler;

FIG. 17 is an illustrative implementation of dynamic logical ring builtwith integrated dynamic traffic management enabled multi-mode switchingedge routers and core routers;

FIG. 18 is an illustrative implementation of dynamic reconfiguration oflogical rings;

FIG. 19 is an illustrative implementation of virtual leased lines withguaranteed bandwidth and latency;

FIG. 20 is an illustrative implementation of a dynamic multi-mode packetscheduler with the dynamic logical connection/ring management module;

FIG. 21 is an illustrative implementation of a dynamic virtual logicalring/connection association;

FIG. 22 is an illustrative implementation of dynamic connections over amesh topology; and

FIG. 23 is an illustrative implementation of distributed packetmanagement with dynamic logical connection/ring management module.

DETAILED DESCRIPTION

Refer now to the drawings wherein depicted elements are not necessarilyshown to scale and wherein like or similar elements are designated bythe same reference numeral through the several views.

Referring to the drawings in general, it will be understood that theillustrations are for the purpose of describing particularimplementations of the disclosure and are not intended to be limitingthereto. While most of the terms used herein will be recognizable tothose of ordinary skill in the art, it should be understood that whennot explicitly defined, terms should be interpreted as adopting ameaning presently accepted by those of ordinary skill in the art.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory only,and are not restrictive of the invention, as claimed. In thisapplication, the use of the singular includes the plural, the word “a”or “an” means “at least one”, and the use of “or” means “and/or”, unlessspecifically stated otherwise. Furthermore, the use of the term“including”, as well as other forms, such as “includes” and “included”,is not limiting. Also, terms such as “element” or “component” encompassboth elements or components comprising one unit and elements orcomponents that comprise more than one unit unless specifically statedotherwise.

Combined with Erbium doped fiber amplifiers, DWDM has dramaticallyimproved bandwidth distance, providing huge reductions in the cost perbit per mile of transmission. DWDM is becoming the universal standard intransmission. Today there are two primary switching technologies,namely, electronic switching and optical switching. These switchingtechnologies are discussed herein.

Electronic Packet Switching (EPS) Technology

Electronic Packet Switching (EPS) converts DWDM signals back toelectrical signals and processes data on a packet-by-packet basis. Ingeneral, EPS routers can be categorized into Input Queued (IQ) switches,Output Queued (OQ) switches, and Combined Input-Output Queued (CIOQ)switches based on where packets are buffered. In an IQ switch, packetsare buffered at input ports and a crossbar switch fabric is used. In agiven time slot, an input of an IQ switch can send out at most onepacket, and an output can receive at most one packet. In an OQ switch,packet buffers are placed at the output ports. All packets arriving atinput ports are immediately transferred to their respective outputports. Unfortunately, an OQ switch requires that the internal switchingfabric operates at a speedup of N, where N is the number of ports of therouter. Therefore, an OQ switch is not scalable. In a CIOQ switch,packet buffers are placed at both input and output ports. The switchingfabric operates with a speedup, which allows up to S packets to betransferred from an input and up to S packets to be received by anoutput in each time slot.

In an ideal OQ switch, a packet only contends for bandwidth with packetsbuffered at the same output port. Fair scheduling in the context of asingle server has been widely studied. Weighted Fair Queuing (WFQ) andits packetized implementation have been shown to be a good approximationof Generalized Processor Sharing (GPS). Deficit Weighted Round Robin(DWRR) provides a computationally efficient version of WFQ. However, theabove results cannot be immediately extended to IQ or CIOQ switches dueto scheduling constraints. It has been shown that CIOQ with a speedup of2 is necessary and sufficient for emulating an OQ switch under variouspolicies such as FIFO, WFQ, DWRR, etc. However, the prevalence of DWDMhas enabled transmission rate at 10 Gb/s, 40 Gb/s, and potentially at160 Gb/s. At these transmission rates, even a CIOQ with a speedup of 2is not practical due to the high electronic buffer speeds required.Parallel Packet Switch (PPS) uses multiple identical lower-speed packetswitches operating independently and in parallel to reduce the bufferbandwidth requirement on individual packet switches. In addition to theelectronic buffer speed, the above approaches require a centralizedscheduler. Although several scheduling algorithms can provide aguaranteed throughput of 50% to 100%, these centralized scheduler basedschemes become impractical as the number of DWDM channels grows, becauseof their scheduling complexity and/or the speedup of the buffer memory.The load balanced switch avoids the centralized packet scheduler and cansupport a large number of linecards. Unfortunately, the cost foroptical/electrical/optical (O/E/O) conversion in electronic packetswitching becomes the limiting factor for scaling to a large number ofDWDM channel.

Optical Switching Technologies

Optical Circuit Switching (OCS)

Optical circuit switching is realized in practice in various forms suchas Optical Add/Drop Multiplexers (OADMs), Reconfigurable OADMs (ROADMs),and Wavelength Routers. OADMs and ROADMs allow one or more wavelengthsto be added or dropped at a node. Wavelengths to be added or dropped arefixed in OADMs and can be reconfigured in ROADMs. However, OADMs orROADMs can only be used to construct linear or ring network topologiesand are not suitable for building mesh network architecture. Awavelength router can switch wavelengths among multiple incoming andoutgoing fibers and can be used to build mesh networks. The coarsegranularity, however, restricts the wavelength routers to core networkswhere optical connections are provisioned to last for months or years.Additionally, connections are needed, just to connect edges, which isnot scalable to the Internet size. Research in OCS is focused on circuitconnection blocking analysis, routing and wavelength assignment (RWA),and traffic grooming. Traffic grooming is a technique that allowslower-speed traffic such as STS-1 (51.94 Mb/s), OC-3, OC-12 and OC-48 toshare lightpaths either statically or dynamically. However, as 10Gigabit Ethernet becomes increasingly popular, benefits of trafficgrooming diminish.

Optical Packet Switching (OPS)

Optical packet switching intends to switch packets and has the finestgranularity among all forms of optical switching. In optical packetswitching, the packet payload is buffered optically while the packetheader is converted to electronic signals and processed electronicallyat each node. When two packets contend for an output, one of them needsto be buffered optically. Both factors—storing optical payload duringheader processing and buffering optical packets for contentionresolution—require optical buffers. Unfortunately, current opticalbuffers do not provide random access. The only way to provide limiteddelays in the optical domain is through Fiber Delay Lines (FDLs). Timedelays to the optical payload are achieved either through the use ofFDLs of varying lengths, or through the use of a fiber delay loop wherethe optical data to be stored circulates through the loop a number oftimes. The lack of optical random access memory severely degrades theperformance of optical packet switching. In addition, implementing FDLsat the scale needed is not practical. For example, a 1 microsecond delaywould require over 1000 feet of FDLs. The synchronization between thepacket header and its payload is another serious concern in opticalpacket switching. After the packet header is processed, it is convertedto optical signals and needs to be combined with the optical payload.Synchronizing the header and the payload is a challenging task that hasnot been yet accomplished beyond the research laboratory.

Optical Burst Switching (OBS)

Optical burst switching is an emerging core switching technology thatallows variable size data bursts to be transported over DWDM links. Inorder to reduce the switching overhead at the core nodes, the ingressedge node aggregates packets from a number of sources destined for thesame egress node dynamically to form a large data burst. An optical pathis created on the fly to allow data bursts to stay in the optical domainand pass through the core routers transparently. This is achieved bylaunching a burst header on a separate control channel ahead of the databurst and setting up the optical path prior to the arrival of the databurst. Since OBS is a relatively new field, discussion of severalimportant aspects is provided herein.

OBS Signaling Protocol:

The Just-Enough-Time (JET) OBS signaling protocol allows the OBS corerouters to use delayed reservations by calculating the projected futureburst arrival time and the burst release time using the informationcarried in the burst header. As a result, the OBS core router can managethe wavelength resources efficiently by reserving the wavelength onlyfor the duration of the burst. While the JET protocol is the prevailingprotocol used for OBS, the other notable OBS signal protocol isJust-In-Time (JIT). Compared to JET, JIT reserves the channel bandwidthwhen a setup message is received, not when the data burst is to arrive,and, therefore, is less efficient in terms of bandwidth usage. It wasoriginally believed that the JIT protocol with instant reservationswould be easier to implement than the JET protocol with delayedreservations. However, it has been demonstrated that several channelscheduling algorithms based on the JET protocols are very efficient.

Burst Assembly:

The OBS ingress edge router aggregates packets into bursts beforeforwarding them to the core network. This process is called burstassembly. Bursts are assembled based on the destination edge routers. Aburst is formed when either of the following conditions is met: (1) thesize of the assembling burst reaches the burst length threshold; or (2)the timer expires. The timeout value restricts the burst assemblylatency and is especially useful under light traffic loads. Burstsusually reach the burst length threshold before the timer expires underheavy traffic loads. Although the threshold only or timer only burstassembly policies have been discussed, the mixed burst assembly schemedescribed above works well under both light and heavy traffic loadswithout much implement overhead. The mixed burst assembly scheme isconsidered as the default scheme for OBS. Based on some variations ofburst protocols, burst connections are established by sending anexplicit burst setup request, and are torn down by sending an explicitburst teardown request.

Burst Scheduling:

In OBS networks, the core routers set up optical paths on the fly, basedon the information carried in the burst headers. This requires an onlineburst scheduling algorithm that can support a large number of wavelengthchannels. The major burst scheduling algorithms are discussed below.Horizon scheduling maintains a single status for each wavelength and isefficient to implement, but it suffers from low link utilization. TheLAUC-VF (latest available unscheduled channel with void filling) keepstrack of the voids (gaps) on each wavelength and has high linkutilization. The complexity of LAUC-VF is O(m), where m is the totalnumber of voids. Min-SV (Minimum Starting Void) is a more efficientimplementation of LAUC-VF which uses a geometric approach by organizingthe voids into a balanced binary search tree. The complexity of Min-SValgorithm is O(log m). However, Min-SV has large memory access overheadfor each burst scheduling request. It turns out that the voids arecaused by the variable offset times between the burst headers andbursts.

Supporting Quality-of-Service (QoS) in OBS:

The offset-based QoS scheme assigns a larger offset time to higherpriority bursts. However, offset-based QoS favors shorter length burstsand has longer delay for higher priority bursts. Intentional BurstDropping and Burst Early Dropping intentionally drop low prioritybursts, therefore, suffer from high overall burst loss probability.Wavelength grouping guarantees worst-case burst loss probability foreach service class at the expense of elevated overall burst lossprobability by restricting the use of wavelengths for each priorityclass. The Look-Ahead Window (LaW) resolves burst contention byconstructing a window of W time units and makes collective decisions onburst dropping. LaW only drops a burst when contention is identified.However, the algorithm has high computational complexity. TheContour-based Priority (CBP) algorithm achieves O(1) runtime complexityyet inherits the optimal burst scheduling properties in, and is suitablefor practical realization in OBS networks.

To summarize, OBS provides an effective means to realize dynamic DWDMnetworks. However, it still has coarse granularity compared to packetswitching as a burst is a collection of hundreds or thousands ofpackets.

Methods and apparatuses for enhancing traffic management in opticalnetworks are discussed herein. More specifically, these methods andapparatuses enable efficient dynamic packet traffic management in DenseWavelength Division Multiplexing (DWDM) networks.

These methods and apparatuses allow dynamic traffic to receive packetlevel services in any of three switching modes: EPS, OCS, and OBS modes.The methods and apparatuses minimize the drawbacks of using only oneswitching mode. Various embodiments that disclose the basic operationsof the current invention are explained as follows.

While the packet switching technologies discussed herein identifyseveral methods, processes, and/or schemes that may be utilized, theyare provided for illustrative purposes. Thus, it is noted that thetraffic management methods and apparatuses discussed herein are in noway limited to the examples methods, processes, and/or schemes discussedherein. It will be recognized by one of ordinary skill in the art thatany suitable methods, processes, and/or schemes known in the art ofswitching technologies maybe utilized with the traffic managementmethods and apparatuses discussed herein.

The Multi-Mode Switching DWDM network architecture provides a set ofmulti-mode switching edge routers and core routers connected by DWDMlinks. Each wavelength in a DWDM link can be individually configured inthe electronic packet switching (EPS), optical circuit switching (OCS)or optical burst switching (OBS) mode. The most suited switching modecan be used to transport individual applications, as well as individualmessage types within an application. More importantly, the architectureprovides a cost effective way to scale the number of DWDM channels bymaintaining a relatively small number of costly electronic switchingports. In addition, legacy optical switching networks can interface withthe proposed DWDM network directly by setting the wavelengths in thefiber to be in the OCS mode.

Concurrent DWDM Multi-Mode Switching:

A multi-mode router can be configured such that all three modes can beconcurrently supported in the multi-mode switching core router. Forexample, four wavelengths w₀-w₃ can be configured in different modes inthe same incoming optical fiber connected to Port 1 of the core router.Wavelength w₀ is the control wavelength in the OBS mode to carry burstheader packets. Wavelength w₁ is the data wavelength in the OBS mode tocarry data bursts. Wavelength w₂ is set in the EPS mode and is used tocarry packets which are switched electronically. Wavelength w₃ is in theOCS mode, and any data sent on that wavelength will follow thepre-established lightpath in the optical switching fabric to the desiredoutput. Each of the four wavelengths is switched based the operation ofthe particular switching mode described above. The outgoing wavelengthsmay be combined at the output onto the optical fiber. Additionaldiscussion of concurrent DWDM Multi-Mode Switching is provided in U.S.application Ser. No. 13/325,544 filed on Dec. 14, 2011, which isincorporated by reference herein.

In the traffic management systems and methods, packet level managementis achieved in multi-mode switching DWDM networks. A multi-mode trafficmanagement module provides packet services through EPS connections, OBSconnections, and OCS connections. Packets sent over an EPS connectionare single-packet entities, and the optical connections are terminatedat the downstream router for potential route lookups. Packets sent overan OBS connection share the same egress edge router addresses. An OBSconnection can be set up for certain durations to handle dynamic trafficfor a special event, a large file transfer, a collection of userapplications, etc. Optical paths set by the OCS mode are relatively longlasting connections that assume infinite lengths until explicitdisconnection occurs. In the traffic management system, one embodimentutilizes an integrated multi-mode traffic management module to providetraffic management to all supported switching modes by treating the EPSand the OCS modes as special cases of the OBS mode with variabledurations. This unified approach provides tremendous benefits wheretraffic management schemes can be dynamically changed based on currenttraffic patterns.

FIG. 1 is an illustrative implementation of a reconfigurable asymmetricoptical burst switching (RA-OBS) network 100 providing a set of RA-OBSedge router(s) 130 and RA-OBS core router(s) 120 connected by DWDMlink(s) 110. RA-OBS edge routers 130 may interface with various networksincluding, but not limited to, virtual private networks (VPN), IPnetworks, wireless networks, passive optical networks (PON), GigabitEthernet (GE)/10 GE, cloud computing, or the like. In the RA-OBS network100, each wavelength in a DWDM link can be individually configured forEPS, OCS or OBS modes. RA-OBS core router 120 switches data based on themode configured for a given wavelength, and routes data accordingly.More specifically, a wavelength configured in the EPS mode is switchedelectronically on a packet by packet basis by the core router; awavelength in the OCS mode is switched at the wavelength level usingoptical circuit switching; and a wavelength in the OBS mode is switchedaccording to optical burst switching protocols. An application canchoose a switching mode that is best suited for the characteristics ofthe entire application or vary switching modes for each message typewithin the application.

Another embodiment is to implement different adaptive schemes under thecurrent invention to achieve integrated dynamic services. At themulti-mode switching ingress edge router, packets may be received ondifferent line interfaces such as IP, Gigabit Ethernet (GE)/10 GE, etc.and may be classified for processing into a desired mode (EPS, OCS, orOBS modes) by a traffic management module. Classification can beperformed at the packet level or based on specific settings such as aparticular line interface. Based on the results from the classifier anddynamic traffic management schemes enabled in the dispatcher, thepackets or traffic streams will be processed according to one of thefollowing switching modes: (1) EPS mode—Packets sent in the EPS mode arequeued and transmitted in the EPS packet processor; (2) OCS mode—Trafficstreams in the OCS mode are sent on pre-established lightpaths via theOCS manager; (3) OBS mode—Packets or flows in OBS mode are assembledinto bursts based on the destination edge router address and sentaccording to OBS protocols. The integrated multi-mode traffic managementmodule is responsible for dynamic multi-mode reconfiguration andsignaling protocols for individual switching modes. All wavelengths arecombined onto the outgoing DWDM link.

The traffic management systems and methods allow dynamic traffic toreceive packet level services in any of the three switching modes, theEPS mode, the OCS mode, and the OBS mode, greatly reducing the need forpure EPS mode service, which is relatively expensive due to O/E/Oconversion. In one embodiment, the packets are dispatched to one of thethree switching modes according to dynamic traffic conditions. As aresult, the switching mode for a particular packet is not fixed untilthe transmission time, which can be in the EPS, OCS or OBS mode. Thepackets are tagged to be sent in one of the three switching modes afterclassification.

RA-OBS network 100 has the following characteristics:

Multimodal: The multimodal switching is provided for by the novelsystems and methods discussed herein. Each individual DWDM wavelengthchannel may be allocated for a different switching mode, therebyallowing multiple switching modes to be utilized simultaneously. Eachfiber can transmit multiple wavelengths, each utilizing differentswitching modes, to allow data to be transferred using multipleswitching modes.

Reconfigurability: The reconfigurability comes from the fact that eachindividual DWDM wavelength channel in the proposed architecture can bereconfigured to carry traffic in different switching modes. In addition,the number of wavelengths in each fiber used for EPS, OCS and OBS can bedynamically reconfigured based on specific traffic demands.

Asymmetry: The asymmetry is due to the fact that in a two-waycommunication, different switching modes can be used in differentdirections to provide the best performance, taking into account thecharacteristics of the data in each direction. For example, intelesurgery applications, the OBS or OCS mode can be used fortransferring medical quality 3D video from the patient site to theremote surgeon site, while using the EPS mode for short robot controlmessages from the remote surgeon site to the patient site.

FIG. 2 is an illustrative implementation of an architecture for a RA-OBSedge router 200. In the ingress direction, packets may be received fromvarious networks by line interface 205 and are sent to ingress trafficmanager 207, which includes classifier 210 processors and dynamicmulti-mode packet processor 212 for various switching modes, forclassification and packet/data separation according to a switching mode.Classification and packet/data processing can be performed at the packetlevel or can be based on specific settings. For example, a particularline interface may specifically be associated with EPS, OBS, or OCS.Based on the results from classifier 210, the packets or traffic streamsare processed according to one or more of the following switching modes:(1) EPS mode: Packets to be sent in the EPS mode are queued andtransmitted on a packet by packet basis; (2) OBS mode: Packets or flowsin the OBS mode are assembled into bursts according to the destinationegress edge router address, and sent according to OBS mode protocols;and/or (3) OCS mode: Packets belonging to an optical circuit are sent onthe lightpaths set up by the optical circuit switching protocols. Inaccordance with the switching mode, the packets or traffic streams areprocessed by EPS mode ingress packet processor 215, OBS mode ingressburst assembler 220, or OCS mode ingress circuit manager 225. In someembodiments, one or more of the EPS, OBS, or OCS modes may not bedesired for traffic management. As such, the correspondingprocessor/assembler/manager may not receive any data from the classifier210. In some embodiments, one or more mode specific processing units maynot be configured. Switch 230 routes data to a desired location whenoutputting to DWDM transmitters 235. All wavelengths from the DWDMtransmitters 235 are combined onto the outgoing DWDM link using aoptical multiplexer (MUX) 240, such as a passive optical multiplexer.For example, packets for EPS, burst headers and burst for OBS, andoptical signals for OCS are combined by MUX 240. In some embodiments,data from the edge router 130 are routed through RA-OBS core routers120. In some embodiments, data from the edge router 130 are routedthrough traditional core router nodes via established lightpaths. Insome embodiments, data from the edge router 130 are routed throughRA-OBS core routers along with traditional core router nodes viaestablished light paths.

In the egress direction, the wavelengths on the incoming DWDM link areseparated using an optical demultiplexer (DEMUX) 245. DWDM receivers 250convert optical signals back to the electronic domain. Switch 255 routesdata to the corresponding traffic processors in egress traffic manager257 based on the switching modes of the wavelengths for switching modespecific processing. For example, packets for the EPS mode are sent toEPS mode egress packet processor 260; converted data bursts and burstheader packets for OBS mode are sent to OBS mode egress burst assembler265; and converted optical data for OCS mode is sent to OCS mode egresscircuit manager 270. Egress classifier 275 inspects the data from thetraffic processors and forwards the data to appropriated line interfaces205 for output to the desired network.

In one embodiment, an integrated multi-mode traffic management moduleprovides traffic management to the EPS, OBS and OCS connections in DWDMwavelength channels, as well as the management of the EPS/OBS/OCScontrol packets as illustrated in FIG. 3(a). Data received by themulti-mode traffic management module may be processed for transmissionvia the EPS, OBS, and/or OCS connections. In various embodiments, theintegrated multi-mode traffic management module may provide individualpacket control to the EPS connections, OBS connections, or OCSconnections as illustrated in FIGS. 3(b), 3(c), and 3(d), respectively.In FIG. 3(b), individually controlled packets are sent through EPSconnections, which are terminated at the downstream router for routerlookups. In some embodiments, the EPS connection may be treated as aspecial OBS connection with an infinite length duration. This allowsmore data to be transmitted optically and avoids the cost of expensiveO/E/O conversion necessitated by other EPS systems. FIG. 3(c)illustrates a embodiment where packets can be individually controlledover OBS mode connections. This is in contrast with traditional opticalburst switching. In traditional optical burst switching, packets areassembled into bursts, which are collections of a large number ofpackets, based on their destination edge router addresses. However, themajor shortcoming of traditional OBS is that once a packet is appendedto a burst, it becomes a part of the burst and the individual packetcontrollability is lost. Therefore, traditional OBS suffers from thecoarse granularity that a burst provides. In the traffic managementembodiments discussed herein, full controllability remains for packetsgoing through OBS connections, as illustrated for example in FIG. 3 (c).In another embodiment, the system provides packet level services to OCSmode connections as shown in FIG. 3(d). In the traffic managementsystems discussed herein, OCS data may be treated (in similar manner asEPS connections as discussed above) as special cases of the OBS modedata. This allows for more data to be transmitted optically between theedge routers and allows OCS data to be handled at the packet level,thereby providing finer granularity than traditional OCS datatransmission. In other embodiments, the integrated multi-mode trafficmanagement module may provide controlled packet level services to theEPS, OBS, and OCS connections as illustrated in FIG. 3(e). By managingEPS, OCS, and OBS traffic as discussed, the traffic management systemsand methods discussed herein may provide finer granularity than othertraditional EPS, OBS, or OCS systems.

An illustrative embodiment of an integrated multi-mode trafficmanagement module 1 is provided in FIG. 4. Packets received by lineinterface 10 on different line interfaces such as IP, Gigabit Ethernet(GE)/10 GE, PON, cloud computing, wireless or the like are sent to theintegrated multi-mode traffic management module 1. Dynamic multi-modepacket processor 20 in the integrated multi-mode traffic managementmodule sends traffic to one of the following mode processing modules:EPS mode processor 30, OBS mode processor 40, or OCS mode processor 50.The dispatching of traffic can be performed based on packetclassification, dynamic traffic conditions, specific settings such as aparticular line interface, and/or the like. Based on the results fromthe dynamic multi-mode packet processor/scheduler 20, the packets ortraffic streams are processed according to one of the followingswitching modes: (1) the EPS mode—Packets sent in the EPS mode arequeued and transmitted in the EPS mode processor 430; (2) the OCSmode—Traffic streams in the OCS mode may be sent on establishedlightpaths via the OCS mode processor 50; (3) the OBS mode—Packets orflows in the OBS mode are assembled into bursts based on the destinationedge router address/application requirements and sent according to theOBS mode protocols. The dynamic multi-mode packet processor 20 alsointeracts with the multi-mode switching control 60 which is responsiblefor dynamic multi-mode reconfiguration and signaling protocols forindividual switching modes. Multi-mode switching control 60 maycommunication with core routers to initiate and/or negotiate request forthe addition/removal of EPS, OBS, OCS mode connections, or a combinationthereof. For example, multi-mode switching control 60 may generateEPS/OBS/OCS control packets for the corresponding EPS/OBS/OCS dataprovided on other wavelengths. All wavelengths are combined onto theoutgoing DWDM link.

In one embodiment, packets are tagged to be sent in one of the threeswitching modes by the dynamic multi-mode packet processor 20 afterclassification. In another embodiment, packets are dispatched to one ofthe three switching modes according to dynamic traffic conditions. As aresult, the switching mode for a particular packet is not fixed, and canbe either the EPS, OCS or OBS mode based on dynamic traffic conditions.In another embodiment, the switching mode of a packet is not assigneduntil transmission time. In some embodiments, two levels of dynamictraffic management may be employed by the dynamic multi-mode packetprocessor 20, the underlining processors for the EPS mode, the OCS mode,and the OBS mode, or a combination thereof.

An EPS mode processor 280 is illustrated in FIG. 5. In order to sendpackets over existing EPS connections, the embedded EPS packet scheduler282 places packets received from the dynamic multi-mode packet processorinto the packet pool 284 according to some criteria (e.g. QoS). Packetsare selected by the embedded EPS packet scheduler 282 to transmit on oneof the EPS mode connections via the EPS transmission controller 286. Inone embodiment, EPS wavelength channel are setup or initiated by the EPSreconfiguration manager 288, and the EPS connections may be treated as aspecial case OBS connection with an infinite length duration until it istorn down. While similar to the treatment of OCS connections as specialOBS connections, the difference is that the EPS channels are routed toelectronic ports of some downstream router instead. Once an EPS channelis setup, packets flow to O/E/O converters for processing. In oneembodiment, to add a new EPS mode connection or to remove an existingEPS connection, the dynamic multi-mode packet processor interacts withthe multi-mode EPS reconfiguration manager 288 to initiate thereconfigurations of EPS connections. In another embodiment, the embeddedEPS packet scheduler interacts with the multi-mode EPS reconfigurationmanager to initiate reconfigurations of EPS connections. In oneembodiment, the EPS connections are static. In another embodiment, theEPS connections are dynamic. Wavelength(s) configured for the EPS modemay be terminated in the downstream router. In some embodiments, the EPSchannels are terminated at the immediate downstream router. In someembodiments, the EPS channels are terminated at non-adjacent downstreamrouters via light paths. The packets sent in the EPS mode are convertedto electronic signals for further processing (e.g. router lookup or thelike). The processed packet is then sent over another EPS modewavelength leading towards the destination.

In one embodiment, the dynamic multi-mode packet processor dispatchespackets to the EPS, OCS, or OCS mode on existing connections. In anotherembodiment, the dynamic multi-mode packet processor dispatches packetsto the EPS, OCS or OCS mode which requires new connection setup, whichmay be set up by one of the mode processors or the multi-mode switchingcontrol.

FIG. 6 is an illustrative embodiment of an OBS mode processor 300, whichenables packetized services in OBS, which provides individual control topackets, regardless of the granularity of the optical burst. Accordingto the traffic management system, packets tagged to be sent in the OBSmode are not associated with particular bursts at the burst assemblytime, as in traditional OBS. Instead, after the multi-mode burstassembler 310 accounts for the packet towards the burst, the packet isplaced into packet queues in the packet pool 320, according to dynamictraffic requirements. The optical entity that the packet belongs to isdetermined dynamically based on certain criteria. In one embodiment, theassociation of the packets with the burst is decoupled from thewavelength resource reservation procedure. The packets may be maintainedin a packet pool 320 after receiving the packets from the multi-modeburst assembler 310. The multi-mode burst assembler 310 may interactwith the embedded OBS packet scheduler 330 for dynamic burst generationand wavelength scheduling. The collection of packets is managed by anembedded OBS packet scheduler 330 which is decoupled from the OBSwavelength scheduler 340. The OBS wavelength scheduler 340 determinesthe wavelength for the outgoing burst. The embedded OBS packet scheduler330 interacts with the multi-mode burst transmission control 350 whichcontrols the transmission of the bursts received from the multi-modeburst assembler 310.

In one embodiment, the multi-mode burst assembler 310 interacts with thedynamic multi-mode packet processor for burst generation and wavelengthscheduling. In another embodiment, the multi-mode burst assembler 310interacts with the embedded OBS packet scheduler 330 for burstgeneration and wavelength scheduling. In another embodiment, themulti-mode burst assembler 310 can create bursts based on applicationsrequirements and send burst scheduling request to the OBS wavelengthscheduler 340 without prior packet arrivals. In another embodiment, themulti-mode burst assembler 310 can create bursts based on burstreservation packets received from applications, customer edge, or thelike, and send burst connection requests to the OBS wavelength scheduler340. In another embodiment, the multi-mode burst assembler 310 canassociate a subset of packets/queues in the packet pool 320 with acertain burst. In some embodiments, bursts are set up with certaindurations. In some embodiments, bursts are set up with infinite lengthuntil they are specifically terminated. In some embodiments, bursts aretransmitted after acknowledgements of connection setup are received. Insome embodiments, burst connections are pre-established before data arereceived using advanced reservation.

In one embodiment, the multi-mode burst transmission control 350interacts with the dynamic multi-mode packet scheduler to assign packetsto bursts. In another embodiment, the multi-mode burst transmissionmodule control 350 interacts with the embedded OBS packet scheduler 330to assign packets to bursts. In one embodiment, such assignments arestatic. In another embodiment, such assignments are dynamic. In anotherembodiment, such assignments occur prior to the transmission of thebursts. In one embodiment, such assignments occur during thetransmission of the bursts. In one embodiment, such assignment is toreduce the latency of real-time packets. In another embodiment, suchassignment is to provide bandwidth and/or latency services to packetsfrom different flows.

In one embodiment, the multi-mode burst assembler 310 receives arrivingpacket information from the dynamic multi-mode packet processor, andadds the packet length to its assembling burst of the same destinationedge router. In another embodiment, the multi-mode burst assembler 310receives arriving packet information from the embedded OBS packetscheduler 330, and the length of the packet is added to the assemblingburst of the same destination edge router. In one embodiment, a burst isformed when the burst length, which multi-mode burst assembler 310 keepstrack of, exceeds some predefined values. In another embodiment, a burstis formed when the burst length exceeds some dynamic threshold. In oneembodiment, once a burst is formed, a burst scheduling request isgenerated and sent to the core routers.

In another embodiment, the dynamic multi-mode packet processor sendspacket length and destination information to the multi-mode burstassembler 310 based on packets that have arrived at the edge router. Inanother embodiment, the dynamic multi-mode packet processor sends packetlength and destination information to the multi-mode burst assembler 310based on predicted packet traffic. In another embodiment, the expectedtraffic arrival time is sent along with the length (duration) and thedestination information to the multi-mode burst assembler 310. Inanother embodiment, the multi-mode burst assembler 310 sets variableoffset values between the burst scheduling request and the transmissionof the burst. In another embodiment, dynamic virtual topologies can beconfigured for specific time durations, or for a certain set ofapplications.

Two levels of dynamic traffic management may be employed under thedynamic multi-mode packet processor, as well as the underlining trafficprocessors in the EPS mode, the OCS mode, and the OBS mode. In oneembodiment, packets tagged to be sent in the OBS mode are queuedaccording to dynamic traffic requirements. The optical entity that thepacket belongs to is determined dynamically based on certain criteria.In one embodiment, such association is decoupled from the wavelengthresource reservation procedure. One embodiment maintains the packets ina packet pool 320, and the collection of packets are managed by anembedded OBS packet scheduler 330 which is decoupled from the OBSwavelength scheduler 340. The embedded OBS packet scheduler 330interacts with the transmission of the optical entities.

With the traffic management systems and methods discussed herein,real-time traffic, priority traffic, per flow/application queuing, orthe like can be supported in the multi-mode switching DWDM networksusing wavelengths configured in any of the following modes: the EPSmode, the OCS mode, and/or the OBS mode. FIG. 7 is an illustrativeembodiment of a dynamic multi-mode packet scheduler 400 supportingreal-time and non-real-time traffic. One embodiment of the dynamicmulti-mode packet scheduler 400 implements desirable packet leveltraffic management schemes and controls the transmission of the opticalentity. For example, to support real-time traffic, traffic arriving atthe dynamic multi-mode packet scheduler 400 is directed to one of thetwo queues: a real-time traffic queue 410 and a non-real-time trafficqueue 420. Packets from each queue can be directed to multi-modeswitching control 430, EPS mode processor 440, OBS mode processor 450,or OCS mode processor 460 to achieve the latency objectives.

One embodiment of the dynamic multi-mode packet processor implementsdesirable packet level traffic management schemes and controls thetransmission of the optical entity. For example, to support real-timetraffic, traffic is directed to one of the two queues: one for real-timetraffic and one for other traffic. Packets from each queue can bedirected to one of the three switching modes to achieve the latencyobjectives. In another embodiment, dynamic multi-mode packet processorsupports per flow queuing to provide both bandwidth and latencyguarantees. Different packet management schemes can be deployed in thedynamic multi-mode packet processor at edge routers allowing themajority of the dynamic traffic to pass through core routers optically,minimizing the number of electronic switching ports needed at corerouter nodes and thus reducing cost.

FIG. 8(a) is an illustrative embodiment of a packet pool 500 in an OBSmode processor. Packet pool 500 implements real-time queue(s) 505 andnon-real-time queue(s) 510. The embedded OBS packet schedule 515 makesdecisions on the packet to be forwarded to multi-mode burst transmissioncontrol 520. FIG. 8(b) is an illustrative embodiment of a OCS modeprocessor 550. Real-time queue(s) 555 and non-real-time queue(s) 560 areprovided by the OCS mode processor 550. The embedded OCS packetscheduler 565 makes decisions on the dispatching of real-time andnon-real-time packets, providing packet level traffic management in OCSconnections. OCS connection manager 570 communicates with embedded OCSpacket scheduler 565 to provide packets to OCS transmission control 575when desired. OCS transmission control 575 outputs the OCS data to adesire wavelength.

In one embodiment, the dynamic multi-mode packet processor interactswith the OCS connection manager 570 to initiate the setup/tear down ofOCS connections. In another embodiment, the embedded OCS packetscheduler 565 interacts with the OCS connection manager 570 to initiatethe setup/tear down of OCS connections. In one embodiment, OCSconnection manager 570 initiates OCS connections by treating OCSconnections as a special case of OBS connection with an infinite lengthduration until it is torn down. Optical paths set by the OCS mode arerelatively long lasting connections that assume infinite lengths untilexplicit disconnection occurs. In one embodiment, the OCS connectionsare static. In another embodiment, the OCS connections are dynamic.

Another embodiment of the invention supports multi-mode per flow queuingto provide bandwidth and/or latency guarantees. FIG. 9 is anillustrative embodiment of a dynamic multi-mode packet scheduler 600supporting per flow/class traffic. Different packet management schemescan be deployed in the dynamic multi-mode packet scheduler 600, whichcan dispatch packets in the OBS, OCS, and/or EPS mode. Queues 610 areutilized to support per flow/class traffic, and queues 610 provide thepackets to multi-mode switching control 620, EPS mode processor 630, OBSmode processor 640, and/or OCS mode processor 650. With per flowqueuing, the next hop to be used is selected for each unique combinationof source and destination IP addresses. Therefore, multiple connectionsbetween the same pair of hosts would require only one selection.

In other embodiments, different packet management schemes can bedeployed in an OBS mode processor and/or OCS mode processor. Forexample, per flow/class queues may be provided in a packet pool 710 inan OBS mode processor shown in FIG. 10(a), in a OCS mode processor 720shown in FIG. 10(b), or a combination thereof. These multi-mode trafficmanagement techniques allows the majority of the dynamic traffic to passthrough core routers optically, minimizing the number of electronicswitching ports needed at core router nodes and thus reducing cost.

FIG. 11 illustrates a dynamic multi-mode packet scheduler 800 utilizinga sequence controller 820. The dynamic multi-mode packet scheduler 800provides a sequence controller 820 coupled to per flow/class queues 810.Sequence controller 820 ensures that packets going to the samedestination router are delivered in sequence. Packets output frommulti-mode packet scheduler 800 are then outputted to multi-modeswitching control 830, EPS mode processor 840, OBS mode processor 850,or OCS mode processor 860. In another embodiment, the multi-mode packetscheduler classifies packets to be sent to one of the three switchingmodes, and a sequence controller for a particular switching mode ensuresin-sequence delivery of packets. In some embodiment, the sequencecontroller ensures packets delivered in the mode arrive at thedestination edge router in sequence based on some metrics. In oneembodiment, the sequence controller ensures packets going through aparticular route arrive at the destination edge router in sequence. Inanother embodiment, the sequence controller ensures packets goingthrough different routes arrive at the destination edge router insequence. In another embodiment, the sequence controller ensures packetsfrom a particular line interface arrive at the destination edge routerin sequence. In another embodiment, the sequence controller ensurespackets from certain applications arrive at the destination edge routerin sequence.

FIG. 12 illustrates an embedded OBS packet scheduler 920 of an OBS modeprocessor utilizing a sequence controller 930. Packet pool 900 providesper flow/class queues 910 that provided packets to embedded OBS packetscheduler 920. The embedded OBS packet scheduler 920 coupled tomulti-mode burst transmission control 940 dispatches packets accordingto sequence controller 930 to ensure that packets going to the samedestination router are delivered in sequence. In another embodiment, themulti-mode packet scheduler classifies packets to be sent to one of thethree switching modes, and a sequence controller for a particularswitching mode ensures in-sequence delivery of packets. In anembodiment, the sequence controller ensures packets delivered in themode arrive at the destination edge router in sequence based on somemetrics. In one embodiment, the sequence controller ensures packetsgoing through a particular route arrive at the destination edge routerin sequence. In another embodiment, the sequence controller ensurespackets going through different routes arrive at the destination edgerouter in sequence. In another embodiment, the sequence controllerensures packets from a particular line interface arrive at thedestination edge router in sequence. In another embodiment, the sequencecontroller ensures packets from certain applications arrive at thedestination edge router in sequence.

FIG. 13 is an illustrative embodiment of a dynamic multi-mode packetscheduler 1000 utilizing an energy controller. The energy controller1020 in the dynamic multi-mode packet scheduler 1000 dispatches packetfrom per flow/class queues 1010 according to energy related metrics toreduce energy consumption. For example, optical/electrical/opticalconversion or route lookup/packet processing incurred on the path may beundesirable for reduced energy consumption. Energy related metrics mayreduce optical/electrical/optical conversion, route lookup/packetprocessing incurred on the path, manage traffic utilizing a suitableenergy related metric, or a combination thereof. The packet can beprovided to multi-mode switching control 1030, EPS mode processor 1040,OBS mode processor 1050, or OCS mode processor 1060. FIG. 14 is anillustrative embodiment of an OBS mode processor utilizing an energycontroller 1130. Packet pool 1100 utilizes per flow/class queues 1110 toprovide packets to embedded OBS packet scheduler 1120. Energy controller1130 in the embedded OBS mode packet scheduler 1120 dispatches packetsto multi-mode burst transmission control 1140 according to energyrelated metrics to reduce energy consumption.

In other embodiments, energy efficiency is achieved at the burst level.FIG. 15(a) is an illustrative embodiment of an OBS mode processorutilizing a energy controller 1215 in a multi-mode burst assembler. Asdiscussed previously, OBS mode processor may provide an OBS wavelengthscheduler 1205, multi-mode burst assembler 1210, packet pool 1220,embedded OBS packet scheduler 1225, and multi-mode burst transmissioncontrol 1230. The energy controller 1215 in the multi-mode burstassembler 1210 assembles bursts according to energy related metrics toreduce energy consumption. For example, energy related metrics mayreduce optical/electrical/optical conversion and/or route lookup/packetprocessing incurred on the path.

FIG. 15(b) is an illustrative embodiment of an OBS mode processorutilizing a energy controller 1275 in multi-mode burst transmissioncontrol 1270. As discussed previously, OBS mode processor may provide anOBS wavelength scheduler 1250, multi-mode burst assembler 1255, packetpool 1260, embedded OBS packet scheduler 1265, and multi-mode bursttransmission control 1270. Energy efficiency is achieved at thewavelength scheduling level. The energy controller 1275 in themulti-mode burst transmission control 1270 is in charge of the bursttransmission in order to reduce energy consumption.

FIG. 16 is an illustrative implementation of an integrated multi-modetraffic management module 1300 utilizing an energy controller 1330. Asdiscussed previously, integrated multi-mode traffic management module1300 may include a line interface 1310, multi-mode switching control1340, EPS mode processor 1350, OBS mode processor 1360, or OCS modeprocessor 1370. The energy controller 1330 interacts with multiplemodules in the integrated multi-mode traffic management module 1300 toreduce energy consumption. For example, energy related metrics mayreduce optical/electrical/optical conversion and/or route lookup/packetprocessing incurred on the path.

In one embodiment illustrated in FIG. 17, the multi-mode edge router1410 with an integrated multi-mode traffic management module sets updynamic logical connections or rings 1430 at the multi-mode core routers1420 based on traffic requirements. Multi-degree scheduling at the corerouter ensures that there are no wavelength conflicts on the sharedpaths. The dynamic logical rings 1430 indicate a pathway for packet(s)through multi-mode core routers 1420, which may be dynamically modifiedaccording to traffic conditions.

In another embodiment illustrated in FIG. 18, the integrated multi-modetraffic management module of edge router 1510 performs automatic trafficsensing and dynamic connection reconfiguration through core routers1520. As the traffic demand for some logical rings 1530 reduces, logicalrings can be dynamically removed 1540. New logical rings are dynamicallyadded 1550 to satisfy new demands on other paths. The virtualconnections/rings 1640 can be setup as virtual leased lines withguaranteed bandwidth and latency, as shown in FIG. 19. Edge router 1610routes data through edge routers 1620 via logical rings 1630.Additionally, virtual leased lines 1640 can be dynamically created for acertain event, a large data transfer, a session, or the like. Thevirtual leased lines can be created with dedicated lightpaths, or withshared lightpaths using the integrated packet scheduling module toprovide guaranteed bandwidth and latency.

In an embodiment illustrated in FIG. 20, the dynamic logicalconnection/ring management module 1730 interacts with the dynamicmulti-mode packet scheduler 1700 to send selected packets 1710 over theconnections/rings. The dynamic logical connection/ring management modulealso interacts with the header control 1720 to send reconfigurationcontrol header to the core routers.

In another embodiment illustrated in FIG. 21, dynamic logicalconnection/ring management module 1830 interacts with the dynamicmulti-mode packet scheduler 1800 and header control 1820. The dynamiclogical connection/ring management module 1830 can dynamically associatea subset of packet queues 1810-1, 1810-2, 1810-n with certain logicalconnections/rings 1840-1, 1840-2, 1840-n. In another embodiment, a newlogical connection/ring can be created when a new session or a set ofnew sessions start, in which case, a reconfiguration control header willbe automatically created.

In another embodiment, virtual connections 1930 can be created over amesh topology, as illustrated in FIG. 22. Edge router 1910 may routedata through a mesh network of core routers 1920 through virtualconnections 1930. For example, edge router 1910 may set up dynamic meshpathway(s) through one or more core routers for selected packets. Packetlevel services are provided by the integrated traffic management moduleover the virtual connections. In another embodiment, edge router 1910and core router 1920 are partitioned into multiple virtual routers usingthe EPS, OBS and/or OCS connections.

In another embodiment, the queuing of packets 2020 are distributed overcustomer edges 2010, as illustrated in FIG. 23. The dynamic logicalconnection/ring management module 2040 interacts with distributedcustomer edges 2010 and dispatches packets over logicalconnections/rings. Header control 2050 communicates with dynamic logicalconnection/ring management module 2040 and generates control packetswhen necessary. In one embodiment, customer edge 2010 is coupled to aswitch 2030 that routes packets as desired. In one embodiment, anelectronic packet switching fabric is used to router packets to thedestined optical interfaces. In another embodiment, the logicalconnections/rings are created using multi-lane optical switchingarchitecture.

While the Dense Wavelength Division Multiplexing (DWDM) multi-modeswitching systems and methods discussed herein specifically focuses onrouter architecture, one of ordinary skills in the art, will recognizethe applicability of this approach to other types of designs andapplications that can significantly impact how IP and optical networkscan be efficiently implemented which would affect the evolution offuture networks.

While the traffic management systems and methods described hereinspecifically focuses on the use of efficient dynamic packet trafficmanagement to Dense Wavelength Division Multiplexing networks, one ofordinary skills in the art, with the benefit of this disclosure, wouldrecognize the extension of the approach to other networks and systems.

Implementations described herein are included to demonstrate particularaspects of the present disclosure. It should be appreciated by those ofskill in the art that the implementations described herein merelyrepresent exemplary implementation of the disclosure. Those of ordinaryskill in the art should, in light of the present disclosure, appreciatethat many changes can be made in the specific implementations describedand still obtain a like or similar result without departing from thespirit and scope of the present disclosure. From the foregoingdescription, one of ordinary skill in the art can easily ascertain theessential characteristics of this disclosure, and without departing fromthe spirit and scope thereof, can make various changes and modificationsto adapt the disclosure to various usages and conditions. Theimplementations described hereinabove are meant to be illustrative onlyand should not be taken as limiting of the scope of the disclosure.

What is claimed is:
 1. An edge router system providing optical burstswitching (OBS), the system comprising: an OBS processor modulereceiving data or burst reservation packets from one or more sources,wherein said OBS processor module comprises a burst assembler receivingsaid data or said burst reservation packets, wherein said burstassembler forms outgoing bursts and initiates burst connection setuprequests to establish a burst connection from the burst reservationpackets, a packet pool temporarily queuing said data, and an OBS packetscheduler selecting packets of said data from said packet pool totransmit said packets under said burst connection as the outgoing burst;and a WDM output link outputting said packets selected by said OBSpacket scheduler.
 2. The system of claim 1, wherein said data or saidburst reservation packets contributing to burst formation, and saidburst assembler decouples said packet pool from said burst formation. 3.The system of claim 1, wherein said OBS packet scheduler selects asubset of packets of said data to be outputted under said burstconnections as the outgoing burst.
 4. The system of claim 1, whereinsaid OBS processor module further comprises a burst transmissioncontroller coupled to said burst assembler for setting up OBSconnections and controlling transmission of burst from the OBS processormodule.
 5. The system of claim 4, wherein the burst transmissioncontroller assigns the packets of said data to the outgoing burst. 6.The system of claim 1, wherein the edge router system treats EPSconnections or OCS connections as OBS connections with an infinitelength until said EPS connections or said OCS connections are torn down.7. The system of claim 1, further comprising an EPS processor module forEPS connections; and an OCS processor module for OCS connections,wherein said OBS packet scheduler selects packets outputted under OBSconnections, said OCS connections, or said EPS connections based ontraffic requirements.
 8. The system of claim 1, wherein said edge routersystem further comprises a connection/ring management module, whereinthe connection/ring management module associates packet queues with aspecific connection or ring pathway.
 9. The system of claim 8, whereinsaid edge router system sets up one or more dynamic logical meshconnections or ring pathways through one or more core routers for theoutgoing burst.
 10. The system of claim 9, wherein the ring pathways aredynamically modified according to traffic conditions.
 11. The system ofclaim 1, wherein the burst assembler sends burst scheduling request toOBS wavelength scheduler without prior packet arrivals.
 12. The systemof claim 1, wherein the burst assembler creates a burst based on a burstreservation packet and sends a burst connection request to the OBSwavelength scheduler.
 13. The system of claim 12, wherein the burstassembler associates subset of packets in the packet pool with a certainburst.
 14. The system of claim 1, wherein the OBS processor modulefurther comprises a sequence controller, wherein the sequence controllerroutes packets in sequence when the packets are routed to a samedestination router.
 15. The system of claim 1, wherein the OBS processormodule further comprises an energy controller, wherein the energycontroller assembles burst according to energy related metrics to reduceenergy consumption.
 16. The system of claim 15, wherein the energycontroller minimizes optical/electrical/optical conversion.
 17. Thesystem of claim 15, wherein the energy controller minimizes route lookupor packet processing incurred on a transmission pathway.
 18. The systemof claim 1, wherein the OBS processor module further comprises awavelength scheduler that determines a wavelength for the outgoingburst.